Cotton Faces New Threat In Tarnished Plant Bug

Mar 15, 2006

The Boll Weevil Eradication Program and worm-controlling varieties have allowed tarnished plant bugs to skip to the top spot as cotton's No. 1 pest.

Once growers removed boll weevils from their lists of pests, they began planting transgenic Bt cotton to control tobacco budworms and cotton bollworms. Producers reduced sprays for those insects, and this allowed tarnished plant bug numbers to grow.

“Boll weevil eradication programs cost millions of dollars and were very successful, but now other insects have become key pests,” says Jim Robbins, a research entomologist with the Mississippi Agricultural and Forestry Experiment Station in Stoneville.

Tarnished plant bugs can live in many plants other than cotton, and this makes them more difficult to control.

“Wild host plants are a key player in the life cycle of the tarnished plant bug,” Robbins says. “They can live on about 170 species of wild hosts across the Cotton Belt, and they can reproduce on more than 100 of these.”

Robbins says scouting is key to controlling the tarnished plant bug.

Angus Catchot, cotton entomologist with the Mississippi State University Extension service, says scientists are seeing some signs of pesticide resistance in the tarnished plant bug.

“Pyrethroid resistance has been documented for some time, but now we are seeing the first signs of resistance to organophosphates,” Catchot says.

“The tarnished plant bug is a serious problem across the state, especially in the Delta region,” he says. “Because of the seriousness of this pest, it has become the No. 1 research focus among applied entomologists in the Midsouth.”